Metal cutting tool



i l l I 2.9 28 29 2a l l i i l I J Aug. 6, 1940. D. H. WEST 2.21o,1o9

I METAL CUTTING TOOL Filed Hay 1o, 1958 {METAL ING r Donald-.H; West, Detroit, Mich, .assignor to The Lapointe This invention relat'es'to-a metal cutting tool capable of general application but particularly adapted for cutting external splines longitudinal splines or". ribs on machine parts which are frusto-conicalin shape;

It is the-general obj'ectof my invention to provide'an'improveditoolfor such purposes, by which extremely accurate work can be produced. A, further object is to provide a tool-"adapted to make a series of progressive partial cuts of gradually increasing depth, by which splines of substantial thicknessmay be easily formed in hard or tough metal. o My invention further relates to arrangements andcombinations of parts which will be hereinafter described and more particularly pointed out in the appended claims. [A preferred form of "the invention is shown in the drawing, in which v I I Fig. 1 is a side elevation of parts of a mautilized'to advantage;

Fig. 2'is a plan view of the tool; I Fig. 3 is 'a partial sectional elevation, taken along the line 3-3 in Fig.2; o I V Fig. 4 is a partial front elevation, looking in the direction of the arrow 4 in Fig. 3; Fig. 5 is an enlarged detail sectional view of. acutting element,taken along the'line"5-5 in Fig. 3; and I v o Fig.6 is a similar view of a finishing element. Referring to the drawing, I will first describe my improved cutting tool and will "then explain the use and advantages-thereof. My. improved cutting tool C preferably comprises a disc Ill having a thickened'hub portion H which is recessed at l2 to receive a driving member I4 (Fig. 1) by which the tool may be angularly advanced and accurately located. The

hub II' is also provided with a cylindrical axial opening IE to receive a supporting shaft l6 and with an enlarged circular recess H to receive the end of a locking collar 18 (Fig. 1), which may be secured on the shaft l6 by a pin I!) or in any other convenient manner. The shaft l6 does not rotate but is intermittently advanced.

The details thus far described are relatively be provided with means by which it may be accurately located andheld fromangular disf placement on a supporting shaft, as l The peripheral surface 20 of the disc III is substantially cylindrical,.except for the provision hine Toolvv .Compamz; :Ma ss a corporation of Maine V or parallel-' sided ribs lengthwise of surfaces of rotation. My

improved cutter is exceptionally useful in cutting hine in which myimprove'd cutting tool may be being sufiicient that the disc Ill Hudson,

ofafcircumferential series of unitary cutting elementsli and unitary finishing elements 22 iii:

which series extends in uniformly spaced relationai oundfl the. entire periphery of the disc lll. The cutting elements 2! "are all substantially similar except in height, and each element 2| comprises sidecutting portions 24 (Fig. 5) separated by a recessed middle portion'having inclined side surfaces 25 and aibottomsurface' 26. The portion-s14 and 25 have or mayhave cuttingedges.

Throughout the series of cutting elements 21', the surfaces 26 are uniformly positioned at equal radial"distances from the axial center of the tool but .the-sideportions '24 gradually and progressively increase in height beyond the peripheral surface 20. The increase in height from one pair of cutting elements to the next will'vary accordingto the, size of thetool and the nature of the material to 'be cut, but in'a typical cutting tool' the increase will *commonly be between .003 and L004",

1 The external side surfaces 21 (Fig. 5)" of the cutting elements 2'l are preferably straight and parallel to the middle radius of the "cutting element." The finishing elements 22" are like the highest cutting "elements 2!, except that the ,outerside' portions .28 are inclined as shown in Fig. 6, and that theinner side portions 29 "are Very slightly nearer together thanthe side. por-' ti'ons' 25 (Fig. 5) of the elements 2|.

My improved cutting tool may conveniently be formed by making all of the cutting elements2l of the same size andshape as the finishing elementsffifand' thereafter grinding away portions o'fvprogressively increasing thickness from the outer edgeiportions of successive cutting elements until thede'sired progressive difference in height of cutting elements is attained. The outer side portions are also ground to the parallel relation shown in Fig. 5.

Having described the details of construction of my improved cutter, the use and advantages thereof will be'apparent by reference to Fig; 1, which shows how a piece of work W mounted on a rotatable inclined work support 40 may have its slightly tapered hub portion 4| provided with a series of spaced external splines which are of uniformcross section throughout their length.

My improved cutting tool C is shown as mount ed on the shaft lipreviously described, and the shaft I6 is supported in a bearing block or slide 44 'which may be vertically reciprocated. Any suitable means may be provided for intermittently moving the work W and the tool C angularly and by predetermined amounts.

In the ordinary operation of the machine, the work W is advanced toward the tool C to a predetermined working position, in which position the first unitary cutting element 2| of the external series will engage the hub M and when reciprocated relative thereto will make two shallow parallel. cuts therein. It is; to be understood that the work is mounted in such a position that the exterior conical surface thereof will be parallel to the path of travel of the tool C at the point of operation.

In the usual procedure, the cutter C is moved downward to make a cut with theacutting ele-,- ment 2W, after which the work is withdrawn, the cutter is moved upward, the work is indexed and again advanced to the cutting position, and a second cut is made by the elementll This procedure is followed until a series of shallow cuts have been made entirely around the hub portion 4|, whereupon the cutterC is advanced one space to bring the cutting element 2i into working position, and a'second series, ofjcutsis then made around .thehub 4|, slightly' d'eepen ing but not widening the previous cuts. Similar operations are thereafter repeated until the last and deepest cutting element 2| in the series is brought into working positionand makes its series of cuts around the hub 4|, thus roughly completing the desired series of external splines or parallel-sided ribs 42.. The two finishing elements 22 are then brought successively toworking position. These finis'hingelements commonly out only on the inclined inner portions and accurately size the splines or ribs on the two sides thereof. v

The work is then removed, a new piece of work is inserted, the cutter is indexed'to initial position, and cutting operations are resumed.

The overall width of the cutting elements 2| is such that the cuts formed thereby slightly overlap on the hub 4i and thereby" remove all of the stock between the finished ribs 42 with substantially equal cuts at e'achside of thespline being formed. The finishing elements 22 are beveled outwardly to brace the cutting portions thereof against side pressure in making the finishing cuts on the sides'of fthe splines. The bottom portions '26 of the cutting elements 2| and the outer end portions of the finishing 'ele'- ments 22 commonly do no cutting.

By use of my improved cutting tool as above described, I am able to form a series of splines on a tapered hub with very great accuracy, so that they are well adapted to fit corresponding internal grooves cut in a conical recess. in an associated piece, these grooves being commonly cut by an ordinary single tooth tool and having the same cross section throughout their length.

Having thus described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claims, but what I claim is:

1. A metal broaching tool for cutting external splines of uniform Width on a conical piece of work o'fcircularfgcross section which comprises a dis'c "having aconcentric and substantially cylindrical periphery and having a plurality of unitary. cutting elements mounted on said peripheryand uniformly spaced apart angularly by non-cutting portions of said cylindrical periphery, the cutting parts of successive cutting elements projecting progressively greater distances from said periphery and each unitary cutting elementcomprising spaced end-cutting edge portions, a normally non-cutting middle bottom portion and end cutting connecting portions, and all of saidcutting portions of a unitary cutting element/ simultaneously engaging the Work and simultaneously operating thereon to produce a single external spline of uniform width extending longitudinally of said conical piece of work. 2. A metal broaching tool for cutting external splines of uniform width"on a conical piece of Work of circular cross section which comprises a disc having a concentric and substantially cylindrical periphery and having a plurality of unitary cutting elements mounted on said periphcry and uniformly spaced apart angularly by non-v cutting portions of said cylindrical periphery, the cutting parts of successive cutting elements projecting progressively greater distances from said, periphery and each unitary cutting element comprisingspaced end-cutting edge portions, a normally non-cutting middle bottom portion and oppositely inclined end-cutting connecting por-' tions, the .end and bottom portions being substantially parallel 'to and concentric with the periphery of said disc and the bottom portions of allcutting elements being at the .same radial distance from'the axis of said disc, and all of said cutting portions of a unitary cutting element simultaneously engaging the work and si- 'multaneously operating thereon to produce a singleexternalspline of uniform width extending longitudinally of said conical piece of work.

3. The combination in a cutting tool as set forth inf clair n 2, in, which additional similar unitary finishing elements are provided onfsaid periphery, saidfinishing elements having inclined inner cutting edges slightly closer together than inthe first-mentioned elements and effective to accurately size said splines widthwise.

DONALD H. WEST. 

